Portable electronic devices, for example, mobile phone, notebook computer, tablet computer, personal digital assistant and media player, have more and more functions, and the users have more dependence on portable electronic device, that is, lots of daily work or job related behavior have to rely on the assistance from portable electronic device. For example, for current mobile phone, in addition to calling and message sending function, usually one or several functions are integrated, for example, photography, positioning, navigation, internet surfing and game, etc.
In order to reach the above mentioned functions and to satisfy the demand of the users, currently, there are lots of portable electronic devices in the market integrating with all kinds of functional devices or modules. For example, in order to possess photography function, lens module is integrated; in order to possess positioning or navigation function, GPS positioning module is integrated; in order to have internet surfing function, wireless network module is integrated; in order to have game playing function, touch sensor and three axes accelerometer, etc. are integrated.
Wherein, three axes accelerometer can detect the acceleration on three axes (that is, X, Y and Z axes) of portable electronic device, then the user's action is reflected to perform corresponding control, for example, the turning and velocity change of the target under control in the game.
In the traditional three axes accelerometer, it is used to detect the included angle change between acceleration and gravitational acceleration of object (for example, the above mentioned portable electronic device), then the tilting angle generated while the object rotates can be calculated, and corresponding control can then be performed. However, when the rotation is not related to gravitational force (for example, the rotation in the horizontal direction), a single three axes accelerometer will be unable to measure the rotational angle change, which might lead to inconvenience to the user.
In order to solve this issue, in addition to three axes accelerometer, the designer or the manufacturer even integrates extra component, for example, gyroscope or digital compass to detect the horizontal rotation of the portable electronic device. However, the integration of these extra components will increase the volume, manufacturing cost and calculation complexity of the portable electronic device.